The present invention relates to passive decay heat removal in a pressure tube light water cooled and moderated reactor with a large power rating on the order of 1,000 MWe.
A large amount of decay energy is continually generated by nuclear fuel after the reactor is shut down. Conventionally, actively pumped redundant cooling systems provide the emergency coolant to remove this decay heat under abnormal conditions such as a loss of coolant accident.
Conventional reactors have the additional disadvantage that their power density profile has a maximum average power ratio or peaking factor of about, 2, even when measures are employed to minimize this peaking.